1. Field of the Invention
The present invention relates to arrow and harpoon guns, and more particularly, to guns which propel a hollow arrow or harpoon using a compressed gas source such as compressed air or CO.sub.2 to propel the arrow.
Harpoon or arrow guns using an energy source such as compressed gas are well known in the art. These devices generally latch an arrow or harpoon into the barrel of the gun and energize the gun under high pressure prior to firing the arrow. The known compressed gas sources vary, and may include portable air bottles, CO.sub.2 cartridges, scuba tanks, and the like. These guns are primarily for underwater use such as for spearing fish, but may be for use in other activities such as hunting.
2. Discussion of the Prior Art
In the prior art, various types of guns are disclosed, along with different types of arrows or harpoons, and several types of compressed air sources. These various devices, however, are subject to several disadvantages which, in many cases, inconvenience the user, and in some cases, require careful and specialized handling of the gun, since the gun when loaded is in a highly volatile condition where the possibility of accidental discharge is a hazard.
Mares, U.S. Pat. No. 2,833,266, discloses a spearfishing gun provided with a hollow-type spear which slides over an inner barrel of the gun and under a short outer barrel located near the handle. A compressible stopper is provided inside the spear tip to seal the open end of the inner barrel so that as the spear is latched, or locked, into the gun, the gun may be energized without leaking. Latching occurs due to a notched area on the shaft of the spear engaging a clip in the gun handle. The gun is energized by an attached compressed air container. This type of gun presents a typical but serious hazard to the user, since the gun is under high pressure while it is loaded and accidental discharge of the spear may occur. Once the spear is in place, the gun is always under an energized condition, so that mishandling may be hazardous.
Englis, U.S. Pat. No. 3,102,525, discloses an underwater dart or spear gun where the dart is placed over a short barrel of the gun similar to Mares. A CO.sub.2 -cartridge is located in the tip of the hollow dart, so that pulling the trigger forces a pointed-tip rod to extend into the dart to puncture the CO.sub.2 -cartridge, thus propelling the dart. This gun is also hazardous and must be carefully handled, since there is necessarily a very short distance from the pointed tip rod to the CO.sub.2 -cartridge, resulting in the possibility of accidental discharge. Furthermore, upon puncture of the cartridge, pressure is allowed to build in the gun, and the arrow is released only after complete depression of the trigger. This device suffers the further disadvantage that the darts are re-usable only after disassembly and replacement of the CO.sub.2 -cartridge.
Enfield, U.S. Pat. No. 2,957,468, is similar to Englis and also discloses a hollow arrow which slides over the barrel of the gun, and which is provided with a CO.sub.2 -cartridge in the tip of the arrow. The arrow is latched, or locked, onto the barrel and a pointed-tip rod moves forward upon pulling the trigger to puncture the CO.sub.2 -cartridge to propel the arrow. This device, of course, suffers the same disadvantages of the Englis device.
Andina, U.S. Pat. No. 2,723,656, discloses a gun in which a hollow dart fits inside the barrel of the gun and latches in place. Pressure is built up in the barrel to pressurize the dart prior to firing. The pressure build-up, of course, imparts the same disadvantage to this gun as described above, in that the hazard of accidental discharge always exists.
The novel arrow gun pursuant to the present invention obviates the disadvantages of the prior art and provides a highly accurate and powerful gun which is also safe to handle whether loaded or unloaded. It relieves the danger associated with prior art guns which energize the gun after the arrow is loaded and prior to firing. Accordingly, accidental discharge and the associated risk of injury is minimized or eliminated in the present invention. The present invention also provides a novel means for holding the arrow in place on the barrel after loading so that latching or locking the arrow in place is eliminated. Accordingly, jamming of the firing mechanism is avoided, and the arrow may be disengaged if necessary without firing the gun simply by sliding the arrow off the barrel.
Several guns disclosed in the prior art attempt to avoid the problem of latching or locking the arrow into the barrel. However, these guns, such as the gun disclosed in Hanshaw, U.S. Pat. No. 2,839,862, use a solid arrow or harpoon which fits into the barrel and is provided with a stopper-like end which seals the barrel after the arrow is inserted so that pressure builds up behind the stopper of the arrow to eventually force the arrow out of the barrel upon firing. Hanshaw also provides a stopper-like seal at the open end of the barrel, so that a hazardous pressure build-up may exist in the event the seal is too tight or the arrow jams. However, if the seal is not tight enough upon firing, the pressure will not be great enough to effectively propel the arrow.
A further disadvantage associated with the guns such as Hanshaw is that, due to the tolerances necessary to effect the proper build-up of pressure, arrows or harpoons with fletching may not be used. The fletching, of course, provides for accuracy in the flight of the arrow after firing. While the use of arrows or darts with fletching is possible in some guns in which the arrow is placed over the barrel, such as disclosed in Englis above, the fletching must be manually aligned upon loading to straddle the sides of the gun to allow for latching the arrow onto the barrel. In addition, if an outer barrel is provided such as that disclosed in Mares, the fletching again becomes prohibitive to the use of the gun.